Remove deprecated DefaultNetworkSimulationConfig

To be landed after 23th October

Bug: webrtc:9630
Change-Id: Ie322fe5428824b29ad51edaaa446121c5511b9ff
Reviewed-on: https://webrtc-review.googlesource.com/c/104600
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25339}
diff --git a/api/test/simulated_network.h b/api/test/simulated_network.h
index 0c5d829..c03b4ca 100644
--- a/api/test/simulated_network.h
+++ b/api/test/simulated_network.h
@@ -63,10 +63,6 @@
   int avg_burst_loss_length = -1;
 };
 
-// TODO(bugs.webrtc.org/9630) remove it after migration to new API.
-// Deprecated. DO NOT USE. Use BuiltInNetworkBehaviorConfig instead.
-using DefaultNetworkSimulationConfig = BuiltInNetworkBehaviorConfig;
-
 class NetworkBehaviorInterface {
  public:
   virtual bool EnqueuePacket(PacketInFlightInfo packet_info) = 0;